One half-cup of water, one fourth-cup of lemon juice, one jalapeño or serrano pepper (roasted, pickled or fresh), two stalks of celery, one-half of a cucumber, one tablespoon of thick yoghurt or one half-cup of buttermilk, one teaspoon of apple cider vinegar and one tablespoon of parsley, all whirled in a blender till smooth. Add water if necessary for processing.